sockets.c

一个基于ucos－ii和lwip的简单telent服务器

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <[e-mail]>
 *
 * Improved by Marc Boucher <[e-mail]> and David Haas <[e-mail]>
 *
 */

#include "lwip/opt.h"
#include "lwip/api.h"
#include "lwip/arch.h"
#include "lwip/sys.h"

#include "lwip/sockets.h"

#define NUM_SOCKETS MEMP_NUM_NETCONN

struct lwip_socket {
  struct netconn *conn;
  struct netbuf *lastdata;
  u16_t lastoffset;
  u16_t rcvevent;
  u16_t sendevent;
  u16_t  flags;
  int err;
};

struct lwip_select_cb
{
    struct lwip_select_cb *next;
    fd_set *readset;
    fd_set *writeset;
    fd_set *exceptset;
    int sem_signalled;
    sys_sem_t sem;
};

static struct lwip_socket sockets[NUM_SOCKETS];
static struct lwip_select_cb *select_cb_list = 0;

static sys_sem_t socksem = 0;
static sys_sem_t selectsem = 0;

static void
event_callback(struct netconn *conn, enum netconn_evt evt, u16_t len);

static int err_to_errno_table[11] = {
    0,      /* ERR_OK    0      No error, everything OK. */
    ENOMEM,    /* ERR_MEM  -1      Out of memory error.     */
    ENOBUFS,    /* ERR_BUF  -2      Buffer error.            */
    ECONNABORTED,  /* ERR_ABRT -3      Connection aborted.      */
    ECONNRESET,    /* ERR_RST  -4      Connection reset.        */
    ESHUTDOWN,    /* ERR_CLSD -5      Connection closed.       */
    ENOTCONN,    /* ERR_CONN -6      Not connected.           */
    EINVAL,    /* ERR_VAL  -7      Illegal value.           */
    EIO,    /* ERR_ARG  -8      Illegal argument.        */
    EHOSTUNREACH,  /* ERR_RTE  -9      Routing problem.         */
    EADDRINUSE    /* ERR_USE  -10     Address in use.          */
};

#define err_to_errno(err) \
  ((err) < (sizeof(err_to_errno_table)/sizeof(int))) ? \
    err_to_errno_table[-(err)] : EIO

#ifdef ERRNO
#define set_errno(err) errno = (err)
#else
#define set_errno(err)
#endif

#define sock_set_errno(sk, e) do { \
      sk->err = (e); \
      set_errno(sk->err); \
} while (0)


static struct lwip_socket *
get_socket(int s)
{
  struct lwip_socket *sock;

  if ((s < 0) || (s > NUM_SOCKETS)) {
    LWIP_DEBUGF(SOCKETS_DEBUG, ("get_socket(%d): invalid\n", s));
    set_errno(EBADF);
    return NULL;
  }

  sock = &sockets[s];

  if (!sock->conn) {
    LWIP_DEBUGF(SOCKETS_DEBUG, ("get_socket(%d): not active\n", s));
    set_errno(EBADF);
    return NULL;
  }

  return sock;
}

static int
alloc_socket(struct netconn *newconn)
{
  int i;

  if (!socksem)
      socksem = sys_sem_new(1);

  /* Protect socket array */
  sys_sem_wait(socksem);

  /* allocate a new socket identifier */
  for(i = 0; i < NUM_SOCKETS; ++i) {
    if (!sockets[i].conn) {
      sockets[i].conn = newconn;
      sockets[i].lastdata = NULL;
      sockets[i].lastoffset = 0;
      sockets[i].rcvevent = 0;
      sockets[i].sendevent = 1; /* TCP send buf is empty */
      sockets[i].flags = 0;
      sockets[i].err = 0;
      sys_sem_signal(socksem);
      return i;
    }
  }
  sys_sem_signal(socksem);
  return -1;
}

int
lwip_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
{
  struct lwip_socket *sock;
  struct netconn *newconn;
  struct ip_addr naddr;
  u16_t port;
  int newsock;
  struct sockaddr_in sin;

  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d)...\n", s));
  sock = get_socket(s);
  if (!sock) {
    set_errno(EBADF);
    return -1;
  }

  newconn = netconn_accept(sock->conn);

  /* get the IP address and port of the remote host */
  netconn_peer(newconn, &naddr, &port);

  memset(&sin, 0, sizeof(sin));
  sin.sin_len = sizeof(sin);
  sin.sin_family = AF_INET;
  sin.sin_port = htons(port);
  sin.sin_addr.s_addr = naddr.addr;

  if (*addrlen > sizeof(sin))
      *addrlen = sizeof(sin);

  memcpy(addr, &sin, *addrlen);

  newsock = alloc_socket(newconn);
  if (newsock == -1) {
    netconn_delete(newconn);
  sock_set_errno(sock, ENOBUFS);
  return -1;
  }
  newconn->callback = event_callback;
  sock = get_socket(newsock);

  sys_sem_wait(socksem);
  sock->rcvevent += -1 - newconn->socket;
  newconn->socket = newsock;
  sys_sem_signal(socksem);

  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_accept(%d) returning new sock=%d addr=", s, newsock));
  ip_addr_debug_print(SOCKETS_DEBUG, &naddr);
  LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%u\n", port));

  sock_set_errno(sock, 0);
  return newsock;
}

int
lwip_bind(int s, struct sockaddr *name, socklen_t namelen)
{
  struct lwip_socket *sock;
  struct ip_addr local_addr;
  u16_t local_port;
  err_t err;

  sock = get_socket(s);
  if (!sock) {
    set_errno(EBADF);
    return -1;
  }

  local_addr.addr = ((struct sockaddr_in *)name)->sin_addr.s_addr;
  local_port = ((struct sockaddr_in *)name)->sin_port;

  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_bind(%d, addr=", s));
  ip_addr_debug_print(SOCKETS_DEBUG, &local_addr);
  LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%u)\n", ntohs(local_port)));

  err = netconn_bind(sock->conn, &local_addr, ntohs(local_port));

  if (err != ERR_OK) {
    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_bind(%d) failed, err=%d\n", s, err));
    sock_set_errno(sock, err_to_errno(err));
    return -1;
  }

  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_bind(%d) succeeded\n", s));
  sock_set_errno(sock, 0);
  return 0;
}

int
lwip_close(int s)
{
  struct lwip_socket *sock;

  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_close(%d)\n", s));
  if (!socksem)
      socksem = sys_sem_new(1);

  /* We cannot allow multiple closes of the same socket. */
  sys_sem_wait(socksem);

  sock = get_socket(s);
  if (!sock) {
      sys_sem_signal(socksem);
      set_errno(EBADF);
      return -1;
  }

  netconn_delete(sock->conn);
  if (sock->lastdata) {
    netbuf_delete(sock->lastdata);
  }
  sock->lastdata = NULL;
  sock->lastoffset = 0;
  sock->conn = NULL;
  sys_sem_signal(socksem);
  sock_set_errno(sock, 0);
  return 0;
}

int
lwip_connect(int s, struct sockaddr *name, socklen_t namelen)
{
  struct lwip_socket *sock;
  err_t err;

  sock = get_socket(s);
  if (!sock) {
    set_errno(EBADF);
    return -1;
  }

  if (((struct sockaddr_in *)name)->sin_family == AF_UNSPEC) {
    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d, AF_UNSPEC)\n", s));
    err = netconn_disconnect(sock->conn);
  } else {
    struct ip_addr remote_addr;
    u16_t remote_port;

    remote_addr.addr = ((struct sockaddr_in *)name)->sin_addr.s_addr;
    remote_port = ((struct sockaddr_in *)name)->sin_port;

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d, addr=", s));
    ip_addr_debug_print(SOCKETS_DEBUG, &remote_addr);
    LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%u)\n", ntohs(remote_port)));

    err = netconn_connect(sock->conn, &remote_addr, ntohs(remote_port));
   }

  if (err != ERR_OK) {
    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d) failed, err=%d\n", s, err));
    sock_set_errno(sock, err_to_errno(err));
    return -1;
  }

  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_connect(%d) succeeded\n", s));
  sock_set_errno(sock, 0);
  return 0;
}

int
lwip_listen(int s, int backlog)
{
  struct lwip_socket *sock;
  err_t err;

  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_listen(%d, backlog=%d)\n", s, backlog));
  sock = get_socket(s);
  if (!sock) {
    set_errno(EBADF);
    return -1;
  }

  err = netconn_listen(sock->conn);

  if (err != ERR_OK) {
    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_listen(%d) failed, err=%d\n", s, err));
    sock_set_errno(sock, err_to_errno(err));
    return -1;
  }

  sock_set_errno(sock, 0);
  return 0;
}

int
lwip_recvfrom(int s, void *mem, int len, unsigned int flags,
        struct sockaddr *from, socklen_t *fromlen)
{
  struct lwip_socket *sock;
  struct netbuf *buf;
  u16_t buflen, copylen;
  struct ip_addr *addr;
  u16_t port;


  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d, %p, %d, 0x%x, ..)\n", s, mem, len, flags));
  sock = get_socket(s);
  if (!sock) {
    set_errno(EBADF);
    return -1;
  }

  /* Check if there is data left from the last recv operation. */
  if (sock->lastdata) {
    buf = sock->lastdata;
  } else {
    /* If this is non-blocking call, then check first */
    if (((flags & MSG_DONTWAIT) || (sock->flags & O_NONBLOCK))
  && !sock->rcvevent)
    {
      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): returning EWOULDBLOCK\n", s));
      sock_set_errno(sock, EWOULDBLOCK);
      return -1;
    }

    /* No data was left from the previous operation, so we try to get
       some from the network. */
    buf = netconn_recv(sock->conn);

    if (!buf) {
      /* We should really do some error checking here. */
      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): buf == NULL!\n", s));
      sock_set_errno(sock, 0);
      return 0;
    }
  }

  buflen = netbuf_len(buf);

  buflen -= sock->lastoffset;

  if (len > buflen) {
    copylen = buflen;
  } else {
    copylen = len;
  }

  /* copy the contents of the received buffer into
     the supplied memory pointer mem */
  netbuf_copy_partial(buf, mem, copylen, sock->lastoffset);

  /* Check to see from where the data was. */
  if (from && fromlen) {
    struct sockaddr_in sin;

    addr = netbuf_fromaddr(buf);
    port = netbuf_fromport(buf);

    memset(&sin, 0, sizeof(sin));
    sin.sin_len = sizeof(sin);
    sin.sin_family = AF_INET;
    sin.sin_port = htons(port);
    sin.sin_addr.s_addr = addr->addr;

    if (*fromlen > sizeof(sin))
      *fromlen = sizeof(sin);

    memcpy(from, &sin, *fromlen);

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): addr=", s));
    ip_addr_debug_print(SOCKETS_DEBUG, addr);
    LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%u len=%u\n", port, copylen));
  } else {
#if SOCKETS_DEBUG > 0
    addr = netbuf_fromaddr(buf);
    port = netbuf_fromport(buf);

    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_recvfrom(%d): addr=", s));
    ip_addr_debug_print(SOCKETS_DEBUG, addr);
    LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%u len=%u\n", port, copylen));
#endif

  }

  /* If this is a TCP socket, check if there is data left in the
     buffer. If so, it should be saved in the sock structure for next
     time around. */
  if (netconn_type(sock->conn) == NETCONN_TCP && buflen - copylen > 0) {
    sock->lastdata = buf;
    sock->lastoffset += copylen;
  } else {
    sock->lastdata = NULL;
    sock->lastoffset = 0;
    netbuf_delete(buf);
  }


  sock_set_errno(sock, 0);
  return copylen;
}

int
lwip_read(int s, void *mem, int len)
{
  return lwip_recvfrom(s, mem, len, 0, NULL, NULL);
}

int
lwip_recv(int s, void *mem, int len, unsigned int flags)